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FreightWaves Classics/Fallen Flags: American Diamond Lines and Black Diamond Steamship Co.

Companies prospered for a time...

This ship was similar to those owned by Black Diamond. (Photo:

An intertwined history  

The Black Diamond Steamship Company (BDSC) was established in 1919 following World War I by J.E. Dockendorff. He sought to build a line of passenger and cargo ships. 

Meanwhile, the American Diamond Lines was founded at about the same time by the United States Shipping Board (USSB). As noted in an earlier FreightWaves Classics article, the USSB was established as an emergency agency by the 1916 Shipping Act on September 7, 1916. Once the U.S. entered World War I, the USSB’s task was to increase the number of U.S. ships supporting the nation’s wartime efforts. The USSB program controlled many U.S.-flagged ships from 1917 until its powers were transferred to another federal agency on March 2, 1934.

Launch of the SS Ambridge in 1919 at Federal S.B. Yard at Kearney. 
(Photo: Federal S.B. Yard)
Launch of the SS Ambridge in 1919 at Federal S.B. Yard at Kearney.
(Photo: Federal S.B. Yard)

From its inception through 1931, the American Diamond Line ran cargo routes between New York and Rotterdam and Antwerp in the Netherlands. In 1929 the USSB put American Diamond Lines up for sale. Two companies lobbied the USSB to purchase American Diamond Lines – BDSC and the Cosmopolitan Shipping Company. The lobbying and appeals were taken all the way to President Herbert Hoover. 

In 1931 USSB sold American Diamond Lines to BDSC and American Diamond Lines became a BDSC subsidiary. BDSC operated 20 ships and was profitable in the 1920s and early 1930s.

Ports of call

The American Diamond Line ships continued their previous routes between Boston and New York to/from Antwerp, Rotterdam and Amsterdam. Black Diamond had weekly routes to Charlottetown, Montreal, Sydney and St. John’s in Canada, while also serving Philadelphia, Boston, Baltimore and Norfolk/Newport News.

The Black Diamond Shipping Company's flag. (Image:
The Black Diamond Shipping Company’s flag. (Image:

The 1930s and World War II

Dockendorff stepped down as a principal executive in 1934. The same year he also sold the only ship he owned (the SS New Britain), which he had purchased in 1918. The other 20 ships in the fleet were owned by the USSB.

Prior to the U.S. entry into World War II, its ships were neutral, and trans-Atlantic trade continued with Allied nations. American Diamond Lines also chartered some of its ships to foreign-flag shipping companies in order to continue its European trade. However, as Nazi Germany overran western Europe and its U-boats began to sink shipping in the Atlantic, much of the lines’ trade ended. 

During World War II BDSC sold most of its American Diamond Line ships. Also during the war the Black Diamond Steamship Company switched to charter shipping operations, contracting with the Maritime Commission and War Shipping Administration. BDSC operated Victory and Liberty merchant ships for the U.S. government. A chartered ship was run by its crew while the U.S. Navy supplied United States Navy Armed Guards to man the deck guns and radio. The most common armaments on these merchant ships were the MK II 20mm Oerlikon autocannon and the 3”/50, 4”/50, and 5”/38 deck guns.

After the war ended there were hundreds of surplus ships and a great deal of competition. Although Black Diamond Steamship Company continued to operate for a decade after the war, it ceased to operate in 1955, due in large part to market changes and increased competition. Ships it owned were sold or scrapped due to age.

Scott Mall

Scott Mall serves as Managing Editor of FreightWaves Classics. He writes articles for the website, edits the SONAR Daily Watch series, marketing material for FreightWaves and a variety of FreightWaves special projects. Mall’s career spans 45 years in public relations, marketing and communications for Fortune 500 corporations, international non-profits, public relations agencies and government agencies.